Are my float levels too high? - Carb flooding

[sccachallenger]

For a, does the pump lever move as soon as the throttle is opened?
sometimes there's a little slack that can be adjusted out by that bolt with the spring on it, lengthen to take out slack.
For b, your secondary float level may be too high.
Other possibilities are leaky needle and seat, and/or o-rings on needle if you have external adjustment.
Finally, what was ambient when this happens?
Excess heat can raise the fuel level, more noticeable after shut down on hot days.
Adding a heat shield under the carb, and blocking the exhaust crossover in the intake manifold will help.
Glad you're back behind the wheel!

[rollo1504]

Hey,

The pump lever move as soon as the throttle is opended but I will try to lengthen that bolt -> Have read between the bolt and lever should be 0,015" of space when lever is at WOT...
Will check the needle and seat at secondary float bowl again (have been already renewed) ... No o-rings as this carb does not have external adjustment

Ambient was a normal sunny day with around 66°F. Further a valley pan with blocked heat crossover is already installed but will also check this out closer as I will redo the sealing of the valleypan very soon.

Aluminum spacer with 0,5" is also already in use.

I really don't believe that it is a fuel boiling problem or a heat problem.

A good idea might be a problem at the gaskets between metering blocks....will also check this...

Actually a yellow cam with screw in hole Nr. 2 is used but I have a sortiment of all other colours as well.... Will try the orange cam.

Size of actually used nozzles is 31.....

Also want to mention that I live around 2500 ft above sealevel....

Yesterday removed the old spark plugs and the positive thing is that all of them are looking exactly the same but the negative thing that all are completely black.... So I would assume that the mixture is way too rich but on the other hand I have to say that its NOTreally puffing that much black smoke out of the exhausts .... Will keep investing on this as well....

I know that I am almost there comparing where I was at the beginning as everything was set up completely wrong....

But as I many times said I am not a mechanic but I am after it to increase my knowledge about this great piece of american history.

Thank you mopar guys

Cheers Roland

[XH29N0G]

I am a little confused by the yellow cam comment.  I have a large yellow cam with my set, but it fits on a larger diameter throttle shaft and is for a 50 cc dominator pump. My guess is that your yellow cam is not this one.  Using hole #2 is supposed to delay the shot a little.  It might be that you should be using hole #1.  There is some information on the youtube video by Holley https://www.youtube.com/watch?v=eiRIfcrc2yA on pump cams that I found useful.

After rereading some of the previous posts, I have some questions and want to make sure I understand your set up.

You have a 400 ci engine and it has a stumble when you step on it. My discussion assumes it is a lean stumble (not getting enough gas) rather than being too much gas (rich bog).

Are you still using the 4160?  I am guessing from what you have written that it is the 4160 rather than the Street Avenger you mentioned in an earlier post.  I assume the jets are what it came with.  Do you know which ones are in it?

For what it is worth, I found with a 670 street avenger that I needed to increase jet sizes as described in an earlier post.  While this was for WOT A/F and that also made a difference with what cam and squirters I needed to use.  I had a manual 383 with 3.23 gears and found that the orange cam hole 1 with 035 to 032 squirters worked well for me. 

[rollo1504]

Hey,

I am still using the 4160 as I want to "set it up correctly" before I swap to the avenger... Lets say its a kind of training of myself...playing around with the old one before installing the new one...

Thanks for the video link.... I also found a great vid concerning adjusting the accelerator pump.... will check this things out again...

The "old" 4160 which is still in use has a 31 noozle and 64 jets installed....

Concerning the pump cam colour and setting I will also check again to be 100% sure how it is set actually....

For further testing I am already prepared as I have received a tuning kit which contains nozzles, pump cams and a sortiment of jets....

Regards

[XH29N0G]

OK,  See what you can do with the cams and nozzles. I bet you can get pretty close.  If it seems like you are needing to really push things then the problem may be somewhere else.

If it comes to working with the Jets you will need to have a way to gauge the A/F at WOT and up at high RPM.  This can be done by reading plugs (I am not good at that) and it can be done with an A/F gauge.  Someone may know what jets are good for your engine and carburetor, but that isn't me.

[sccachallenger]

Sounds like you're doing all the right things to keep the carb cooler.
I would think if it was a gasket causing the dripping fuel, it would also drip while the engine is running, not just after shutdown.
lowering the float a small amount may be all you need.
I think you understand that changing the pump cam will probably mean re-adjusting the spring on the lever.
And make sure you're not overtaxing anything at wide open throttle, with the new cam/lever position.
And changing to a larger nozzle size is pretty easy, and may help your problem.
I don't understand why the plugs are black, is the vacuum advance hooked up?
Are they the correct heat range spark plugs?
Does the choke open all the way when warmed up?
Are you running a thermostat in the engine?

[XH29N0G]

I missed that about the plugs.  All of those are good points.  I also believe it is possible for excessive idling to lead to carbon deposits on plugs which is black (oily black is wet looking).  The time I had it was a combination of idling and heat range.  For reading plugs, I am told you want to test them after running it up through to WOT. 

[rollo1504]

Hey Folks!

- Installed new orange pump cam and put screw in to 1 as it was installed a ?yellow? cam and screw was set to 2.
- Adjusted pump cam to lever distance to 0,015" as it was around 0,030"

- Installed fuel pressure gauge -> Shows permanently 7,5-8 psi when engine is in idle or at WOT ... ... ... car was not driven... Motor was in Park

- Experimenting with noozles -> Status = pending
- Experimenting with jets -> Status = pending

- Took a picture of the OLD plugs (please see enclosed pix) -> ATTENTION: These plugs have been installed eversince I got the car 3 years ago.
Installed new NGK plugs recommended by RON -> Visual check of new plugs -> PENDING

- Manual Choke installed -> Choke does open all way when engine is warmed up and there is no binding at all
- Installed new thermostat and thermostat was working fine but will check temperatures again next time

- Have also seen dripping fuel from secondary shaft when engine was running !!! I have read somewhere that there should be some teflon bushings inside. May they be damaged? Do they also normally prevent dripping fuel?....

>>> When engine is warmed up and pedal is pushed it revs up pretty fine BUT I could find out when pedal is pressed AND hold around 30% after 2-3 seconds engine stumbles just a little bit and sometimes it detonates out of the exhausts -> It does NOT backfire. If then pedal is pushed more or to WOT everything sounds nice. No backfire nor detonation at exhausts<<<

If I drive it it pulls pretty nice through all RPM ranges.... As said If pedal held for a couple of seconds at 30% it begins to stumble for a short period... If pedal is pressed more then it continues revving up without any problem.

Thanks guys! You are great!

Roland

[BSB67]

- What problems still persist:
a) If engine is shut off after driving around and I let the car in park after some minutes I still can see that fuel is dropping out from the secondary throttle shaft on both sides of the shaft - One drop every 3 minutes which stopps after 15 minutes..... Still do not know whats going on.... Any suggestions ?

b) If I play with the pedal and push it from off idle to WOT it hesitates for a very very small time -> Jets to small or accerlator pump? Not sure. If I drive off with 50-70% pedal down it does NOT hesitate...

a)
- Are any of the boosters dripping during idle or after you shut it down?
- Rear floats too high
- Rear N/S leaking
- Shaft bushing and maybe shaft could be replaced but it is probably not that bad IMO.  The issue is not really the gas leaking, but the vacuum leak that it is likely causing.

b)
- Is the bog you describe in park/neutral our under power going down the road? 
- Have you visually checked to see if the squirters are actually functioning properly?
- float on primary side too low
- Power valve opening too late.
- Squirter too small
- some spec of dirt someplace it should not be in the carb
- timing
- idle mixture too lean (possible, but less likely)
- vacuum leak (unlikely based on your description)
- IFR too small (unlikely)

[sccachallenger]

I think the only way fuel can drip from the secondary throttle shaft is as was stated, the boosters on that side are dripping.
Take a strong light and look into the secondary side, you shouldn't see any fuel dripping at idle!
Which we believe can only be caused by the reasons given.
Now, If you have a way of lowering that fuel pressure, I'd certainly try to get it below 6 lbs at idle.
But ONLY after verifying that float, needle and seat, and float level are "perfect"

[rollo1504]

Hey,

@BSB67: Sorry but what does Rear "N/S" leaking mean?
- Concerning the floats I need some time as you know it is a closed system
- Is the bog you describe in park/neutral our under power going down the road?
> I would not call it a bog, I would call it stumbling and YES it is also when engine is in Park/Neutral.... How it behaves under load I still need to test...
- Have you visually checked to see if the squirters are actually functioning properly?
> As far as I can see it I would say they are working as they should but I will make a video and put it to youtube that you guys can see it....

@sccachallenger:
You mean the venturi boosters? No was not able to see it but will also check it again..
Fuel pressure: Actually a new stock mechanical fuel pump is in use.... And the newly installed gauge tells me 7,5-8 psi BUT i have another testing gauge... I will hang this one in as well to ensure that both gauges are telling the same story.... Do you guys know about stock mechanical fuel pumps which provide more than 6,5 psi? I do have a fuel pressure regulator from Holley but not installed yet.... If the other gauge is also telling around 8 psi then I will install the regulator....

New questions:
Today I just had a little bit of time to have a closer look to my NEW Holley Street Avenger carburetor.... and the very first thing what I could see was that the T-Slot at the secondaries is completely covered and not adjusted to look like a square.... So my question is now: Is this correct? Just asking as I might think to have read somewhere that it is very important to set the secondary throttleblades so that the T-Slot is looking like a square but on this completely new carb the T-Slot is completely covered.... So is that right? Is the "square"-adjustment only important for the primaries or ALSO for the secondaries?

If motor is warmed up, it idles very smoothly with new dist from Ron and if set IN GEAR - my vacuum gauge tells me 16,-17 ... Is this a good value?

Next question which came right now to my mind is to check if the throttle plate which is mounted to my old carb is really a correct throttle plate for this application..... Will check that as well.... Just to be sure...

Did not have more time for testing today but will continue tomorrow.....

Thanks so far

Roland

PS: Will try to make a good video to give you guys an overview about the actual situation....

[BSB67]

Again - Check for dribble from the boosters. This takes 30 seconds

Check the float levels.  It is the next thing to do.  It'll take 15 min.

You cannot tune the carb by winging the throttle in park/neutral.  The only way to diagnose and tune off idle is by driving it.  Don't try to tune it that way.

N/S = needle and seat.

You need to check the basics I listed.

[rollo1504]

Hey Folks!

First the "good" news:

- I was driving around near my house for about 20 minutes and tried several things
a) Steady drive with around 35-40 MPH -> Drives perfectly
b) Start off idle to WOT -> Succeeded in doing a small burnout. The only thing which I could notice (BUT ONLY ONCE) -> was a single detonation at the carb but could not reproduce it...
c) Checked dripping fuel at secondary throttle shaft with several stopps on the road -> NO DRIPPING!

- Installed a fuel pressure regulator as without it there is a pressure around 7,5-8 psi
a) Drove around WITH regulator installed at 6,5psi - Drives fine
b) Drove around WITHOUT regulator at 7,5-8 psi - Drives fine and behaves equally as WITH fuel pressure regulator.....

- Checked if secondary boosters are dripping fuel when warmed up engine is in park and idles AFTER coming back from pushing her down the road:
> NO THEY ARE NOT!

- What else did I find:
> I could find out that fuel drips when engine is shut off AND I could also see that ALL 4 srews which hold the intake manifold to the heads are SWEATING....So another culprit in my opinion is that I really need to renew the sealing of the intake manifold.... Will do it as soon as possible.

Open points:
- Checking the float levels -> Question please: HOW to check this if primary and secondary bowls are completely closed. I do not have the possibilty to see the float level. Neither are is a screw to remove to see the level nor sight windows.

And NOW the BAD NEWS:

My old 4160 carb is BROKEN  
As I was removing the squirter to check again which size it has I could see a small peace of the thread where the screw which holds the squirter in place broke off......

I had a closer look at the thread and could see that it was completely worn out and damaged as well by one of the f...... preowners........

So I cant use the carb anymore and I will have to continue with the new carb....
Buying a new mainbody does not make sense for me.....

So I will remove the intakte an redo the sealing as RON kindly explained me how to do it....


Will be back soon....

Thanks for all your inputs...

Cheers Roland

[sccachallenger]

Sorry to hear about the damaged threads, I've not had this problem, previous user may have overtightened due to missing/damaged gaskets leaking.
Do some searching, there may be a repair procedure.
I may have missed this, but we're assuming your vacuum advance is hooked up and functioning properly? This is very important for fuel economy and cleaner spark plugs.
Your spark plugs look dry to me which is good, but way too black!
if it's working properly, try a leaner main jet
Hope someone comes up with a repair procedure for the nozzle screw, they don't need to be very tight if both gaskets are in good shape.
I might try using a little epoxy on the threads to hold it in for now.

[rollo1504]

Naaaah...

Won't waste time right now on repairing it...

Will continue with the new carb but before I will take the opportunity and will remove the intake and valley pan and redo the whole sealing first ...

Vacuum advance is hooked up and works as far as I understand it...

Have checked the noozle screw on my new carb, and yes you are right, they really are not very tight...

Regards

[rollo1504]

As I said it was time to take the intake off....

And what could I say?? 

Have a look on your own....

Will post again pictures as soon as it is cleaned....

Roland

[rollo1504]

Guys!

Can someone please tell me the amount of torque I need to bolt on the valley pan....

Is the torque needed for the intake manifold screws the same as the torque needed to bolt on the endstraps of the valley pan?

Can't find them actually....

New valley pan arrives tomorrow and I do not want to waste time looking for the torque specifications then...

Thanks!

Cheers Roland

[sccachallenger]

fasteners are very small, don't over tighten!
I think 15 foot lbs. should be plenty!
Truthfully I doubt I ever checked, just went by "feel" and used a little sealant on the block.
40 is way too much, you'll stretch or break them.

[rollo1504]

Ok. Thanks! Will consider that....

Will be back soon with some results....!

Roland

[BSB67]

35 I think.

1) did you check for leaks from the previous set up?
2) be sure to check that the intake and head meet up properly.

Intake gaskets don't just start leaking.  If it was actually leaking, it's likely an alignment issue that won't fix itself by replacing the pan.

[rollo1504]

Hey,

1) Could find out that the teflon "bushings" inside of the sec throttle shaft were completely worn out/damaged... Do not ask me how this can happen... Maybe some poor guy installed them wrong or with wrong tools... Don't know...Further comparing to the first float bowl it seemed that the sec float level was correct but the needle was not well installed during rebuild which could have caused the issues I had but will not find it out anymore because I can't use this carb with the broken main body anymore...

2. The amount of RTV for the sealing of the intake manifold was way too less and obviously the bolts were torqued way too much which obviously destroyed the sealing. Further around the heat cross over there was no RTV used at all as well as NO gaskets have been used at least...

3. One of the screws which tighten down the strips of the valley pan broke off obviously during last bolt on process... This also lead to malfunctioning of sealing the valley pan 100%...


That was (I think so) the root cause of fuel "dripping" and being inside the valley pan which I asked for what it is in the very first picture of this thread...

Ron (firefighter) was very kind and told me exactly how to install the new valley pan and how/where to use the RTV in a correct way to get a good sealing without any leak not using the paper gaskets...

I will do it as Ron described it....

Will post more pictures later after the cleaning and installation process so that you (experts) :-) can see what I am doing....

Thanks for all you greatness and suggestions.... Would really have been lost without you guys..

More to come soon...

Regards

Roland

PS: Sorry for my bad english again and the mistakes I made during writing this post but hopefully you understand what I want to tell you.... :-)

[sccachallenger]

Glad your float level was "correct", you can still try a lower setting as a tuning tool.
This is what we were trying to tell you.
Also, many people will hold a carburetor or fuel bowl assemby upside down and blow into the fuel inlet, lifting the float will let the air escape, should stop when you let go.
This may reveal a loose or worn needle and seat.
Worth doing on a brand new carb. as a test.

[rollo1504]

Damn!

Cleaned, everything today, re-sealed pan and intake... snugged down the whole thing... Final bolt on will be done tomorrow....

BUT

as I was completely connected to the "Matrix" during work, totally focused not making anything wrong... I completely forgot to take some pictures for you guys....

SORRY!

What have I done so far:

- Removed intake manifold, old valley pan, old sealing and cleaned everything as good as possible and took care of preventing dust and dirt going somewhere into the head ports, camshaft etc....
- Put RTV around cylinder head ports as well as along the bottom end of the head casting from end to end underneath the intake ports
- Put a bead on the ends of the block with an extra dab in all 4 corners
- Put valley pan in place, installed end straps end bolts and just snugged the bolts down enough to keep valley pan in place
- Put RTV around the intake port openings
- Set intake manifold in place, installed bolts and just snugged them up enough to hold intake in place

- RTV is now curing overnight and well be finally tightened down tomorrow....


Thats how Ron described it to me to do so....

Regards

[rollo1504]

Well guys I am back with really good news!

Tightened everything down with personal feel and I think it is working!

Installed new carb and adjusted idle mixture, idle speed, fuel levels... As I am living 2400 feet above sea level I decreased main jets one size.
Engine idles very smoothly (vacuum gauge shows steady 17 in PARK) and drives great overall. No backfire/detonation under full load.

If start off WOT it pulls nicely.... maybe it just hesitates just a little bit but then pulls straight through all RPM ranges smoothly.

Was her driving around for about 20 minutes and checked then intake manifold and valley pan concerning fuel leaks - NOT EXISTANT ANYMORE !
So I think I did the sealing right....

What "problem" or "misbehavior" I recognized 2 times after letting off pedal when it WOT was that engine stalled. I went from idle cruise to WOT and after a put my foot quickly off the pedal so the RPM dropped and 2 times then the engine stalled.... Tried to reproduce the error but was not succeeding in it. I think if I remove foot from pedal after WOT very quickly the engine comes close to stall. If I put off my foot not that quick engine feels like NOT coming close to stall....

Can you tell me concerning this behavior where to look at?

Did NOT touch the squirters, power valve, pump cam and pump lever so far - Its still all factory set....

Will "tune" it later furthermore.... But for now I am good to go ... Am I?

Will try to make a video for you guys to hear/see how it idles and sounds like....

But for now have a look at the enclosed pictures...

Thanks!

Roland

PS: Sorry forgot another thing to ask... If I put her IN GEAR the vacuum pressure drops from 17 to 12 or 13.... Is that a normal value? Should the vacuum when in gear not be around 10? Just asking...

[cdr]

for one thing ,get that fuel line OFF the upper radiator hose